/* DISPLAY 1280x800 AMPIRE AM1280800N3TZ */
am128080n3tz: am1280800n3tz {
clock-frequency = <71000000>;
hactive = <1280>;
vactive = <800>;
hback-porch = <50>;
hfront-porch = <50>;
vback-porch = <5>;
vfront-porch = <5>;
hsync-len = <60>;
vsync-len = <13>;
hsync-active = <0>;
vsync-active = <0>;
de-active = <1>;
pixelclk-active = <0>;
};
/* DISPLAY 1024x600 AMPIRE AM-1024600LTM LVDS */
am1024600l: am1024600l {
clock-frequency = <51200000>;
hactive = <1024>;
vactive = <600>;
hback-porch = <0>;
hfront-porch = <320>;
vback-porch = <0>;
vfront-porch = <35>;
hsync-len = <1>;
vsync-len = <1>;
hsync-active = <0>;
vsync-active = <0>;
de-active = <1>;
pixelclk-active = <0>;
};
/* DISPLAY 800x480 */
ph800480t013: ph800480t013 {
clock-frequency = <33300000>;
hactive = <800>;
vactive = <480>;
hback-porch = <46>;
hfront-porch = <210>;
vback-porch = <23>;
vfront-porch = <22>;
hsync-len = <1>;
vsync-len = <1>;
hsync-active = <0>;
vsync-active = <0>;
de-active = <1>;
pixelclk-active = <0>;
};
};
port@4 {
reg = <4>;
lvds0_out: endpoint {
remote-endpoint = <&in_lvds0>;
};
};
};
};
Anyway, now I am doing the same stuff for compatibile property of the
panel, because Linux wants to have a timing hardcoded in the
panel-simple instead of getting them from the timing section of the
device-tree.
This is a very lack of feature to me. But now, it is quicker to use the
bootloader to compile the correctness of the compatible property to a
almost-identical-timings found in the panel-simple.c...
The other way is to add a edid chip (@ 0x50) for every panel I add, so
to let the EDID stuff to discover what is connected or not to the lvds
board.
This issue can not simply solved in this board, because I do have an
internal eeprom at address 0x50, but it can not be usable for EDID stuff.
So I have two options:
1- let the imx-ldb.c code in the kernel to probe (simple-panel and edid)
and *add* a way to parse the device-tree for adding mode timing property
using the display-timing stuff. (this means kernel patch)
2- look for a common timings from an existing displays in simple-panel.c
and pass them to the compatibile property of the panel in the
device-tree via bootloader.
The step no.2 is the quickest to me. But the ugliest too. ;-)
Any hint?
Regards,
Looking at the parallel-display.c (drivers/gpu/drm/imx) in the function
imx_pd_connector_get_modes() there are 3 ways of defining the
display-timing:
struct imx_parallel_display *imxpd = con_to_imxpd(connector);
struct device_node *np = imxpd->dev->of_node;
int num_modes = 0;
1st mode: getting mode from panel compatibile string, i.e. like having:
compatible = "innolux,g101ice_l01", "simple-panel";
in the device-tree.
if (imxpd->panel && imxpd->panel->funcs &&
imxpd->panel->funcs->get_modes) {
num_modes = imxpd->panel->funcs->get_modes(imxpd->panel);
if (num_modes > 0)
return num_modes;
}
2nd mode: having a edid eeprom somewhere connected to the parallel
display on i2c.
if (imxpd->edid) {
drm_mode_connector_update_edid_property(connector, imxpd->edid);
num_modes = drm_add_edid_modes(connector, imxpd->edid);
}
3rd mode: parsing the device-tree for a node with display mode of native
mode property.
if (np) {
struct drm_display_mode *mode = drm_mode_create(connector->dev);
int ret;
if (!mode)
return -EINVAL;
ret = of_get_drm_display_mode(np, &imxpd->mode,
&imxpd->bus_flags,
OF_USE_NATIVE_MODE);
if (ret)
return ret;
drm_mode_copy(mode, &imxpd->mode);
mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
drm_mode_probed_add(connector, mode);
num_modes++;
}
return num_modes;
The 3rd option lacks in the imx-ldb.c device drivers.
If added this could be a simple way of using the correct timings in the
device-tree to pass to panel in ldb device driver.
Any comment?
--
Eurek s.r.l. |
Electronic Engineering | http://www.eurek.it
via Celletta 8/B, 40026 Imola, Italy | Phone: +39-(0)542-609120
p.iva 00690621206 - c.f. 04020030377 | Fax: +39-(0)542-609212
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